Turbine meter having improved accuracy

ABSTRACT

The conventional axial flow turbine type liquid meter has a tubular casing and a streamlined cylindrical core coaxial with the cylindrical casing. The cores are generally made in two parts which are separated with a rotatable turbine wheel in between, with blades which are operated by the liquid flow in the annular portion between the core and the casing. Such meters are found to be nonlinear when used with high viscosity liquids. In general they show a greater flow than the true flow when the viscosity is high. It is advantageous to introduce a viscous drag on the rotor to compensate for this over-indication. In this invention the rotor wheel is constructed with a hub, an annular plate perpendicular to the axis of the wheel extending out from the hub and a cylindrical flange mounted on the outside of the annular plate, the flange carrying the plurality of radial blades. This construction forms an annular depression in one or both sides of the wheel. The invention involves providing an extension tubular portion to the inner end of one or both of the upstream and downstream parts of the central core. These extensions cooperate with the annular depression to provide narrow spacings between the extensions and the depression whereby the viscous liquids in this meter can provide sufficient drag on the wheel to correct for the overindication. The tubular extensions may be of fixed spacing relative to the wheel or may be of variable spacing controlled by means exterior of the meter. Means are also indicated for flowing liquid into the drag space of the annular depression to insure that there is always liquid in the drag space of the same type, nature, and viscosity as that flowing through the meter.

lJnited States Patent 1 Clinton Sept. 11, 1973 1 TURBINE METER HAVINGIMPROVED ACCURACY William I). Clinton, Tulsa, Okla.

[73] Assignee: Signet Controls, Inc., Tulsa, Okla.

[22] Filed: Nov. 5, 1971 21 Appl. No.: 195,974

[75] Inventor:

[52] US. Cl. 73/231 R [51] Int. Cl. Golf 1/10 [58] Field of Search73/229, 231 R, 231 M [56] References Cited UNITED STATES PATENTS3,518,881 7/1970 Erickson 73/231 R 3,248,944 I. 5/1966 Karlbyetah 73/231R FOREIGN PATENTS oR'APPLIcATIoNs 738,431 10/1955 Great Britain 73/231Primary Examiner-Richard C. Queisser Assistant Examiner-Arthur E.Korkosz Attorney--Head & Johnson [57] ABSTRACT The conventional axialflow turbine type liquid meter has a tubular casing and a streamlinedcylindrical core coaxial with the cylindrical casing. The cores aregenerally made in two parts which are separated with a rotatable turbinewheel in between, with blades which are operated by the liquid flow inthe annular portion between the core and the casing. Such meters arefound to be nonlinear when used with high viscosity liquids. In generalthey show a greater flow than the true flow when the viscosity is high.It is advantageous to introduce a viscous drag on the rotor tocompensate for this over-indication.

In this invention the rotor wheel is constructed with a hub, an annularplate perpendicular to the axis of the wheel extending out from the huband a cylindrical flange mounted on the outside of the annular plate,the flange carrying the plurality of radial blades. This constructionforms an annular depression in one or both sides of the wheel.

The invention involves providing an extension tubular portion to theinner end of one or both of the upstream and downstream parts of thecentral core. These extensions cooperate with the annular depression toprovide narrow spacings between the extensions and the depressionwhereby the viscous liquids in this meter can provide suflicient drag onthe wheel to correct for the over-indication. The tubular extensions maybe of fixed spacing relative to the wheel or may be of variable spacingcontrolled by means exterior of the meter.

Means are also indicated for flowing liquid into the drag space of theannular depression to insure that there is always liquid in the dragspace of the same type, nature, and viscosity as that flowing throughthe meter.

8 Claims, 4 Drawing Figures Patented Sept. 11, 1973 3,757,578

2 Sheets-Sheet 1 l/VVE/VTOR,

WILLIAM D CLINTON N 0 mm mu NC Wm WM r m L w W H v1 6 ATTORNEYS PatentedSept. 11, 1973 2 Sheets-Sheet 2 w j? A 7 v 00H, 7 m K m O w W F FIG.

TURBINE METER HAVING IMPROVED I ACCURACY BACKGROUND OF THE'INVENTION l.Field of the Invention This invention lies in the field of liquidmetering devices.

More particularly, it is concerned with axial flow, turbine type meters.

Still more particularly, it is concerned with an improvement in suchturbine meters whereby a viscous drag is applied to the turbine rotor soas to provide a more linear indication of the meter with flow fordifferent viscosities of flowing liquid. I

2. Description of the Prior Art There is considerable art in theliterature and in the patents covering turbine type flow meters of theaxial flow type.

One of the patents on this subject; namely, U. S. Pat. No. 3,248,945,granted to H. Karlby et al. entitled, VISCOSITY COMPENSATED TURBINEFLOW- METER, which was issued May 3, l966, discusses the problem ofnonlinearity of those meters which are requiredto meter liquids ofdifferent viscosity.

In this patent, a number of ways are indicated for compensating for thisnonlinearity. These generally provide a cylindrical drum arranged to berotated within a cylindrical tube with some of the metering fluidarranged to pass through the annular space between the drum and thecylinder. I g

In general, the apparatus design in the prior art devices is extremelycumbersome, complex, delicate, and expensive.

SUMMARY OF THE INVENTION These limitations-of the prior art devices,such as those of H. 'Karlby, et al. are overcome, and the objectives ofthis invention are fully met by the design to be described. I

In this invention the central core is divided into two parts, anupstream, streamlined, cylindrical portion and a downstream portion.Both are held in position in the tubular casing by means of radialvanes. They are locked together by a long bolt with a spacer means sothat the turbine wheel is free to rotate in the longitudina l spacebetween the two portions.

The invention lies particularly in the design of the rotating turbinewheel and the-cores. The turbine wheel provides on one, or-both, sidesof the wheel, annular depressions between anouter cylindrical flange, aperpendicular a'r'inular plate, and a cylindrical hub. The core portionshave tubular extensions on the inner ends of one or both of the coreportions such that when the instrument. is assembled the extensions fitwithin the annular depressions and provide clearances between theextensions and the rotating wheel, of the desired dimension, so as toprovide the viscous drag required.

Means are also provided for introducing liquid flowing through the meterinto the annular space or spaces, so that it is caused'to flow throughthe small clearance areas to provide the viscous drag.

It' is therefore the primary object of this invention to provide anextremely simple, inexpensive and rugged design of turbine flow meterthat has means for compensating, the rotating wheel for the viscosity ofthe liquid beingmetered.

These and other objects of this invention and a better understanding ofthe principles of the invention will be evident from the followingdescription taken in conjunction with the appended drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows in elevational sectionthe complete details of the improved turbine meter.

FIG. 2 is a section taken along the line 22 of FIG. 1.

FIG. 3 represents a section of the instrument taken along the line 3-3of FIG. 1.

FIG. 4 is a partial cross-sectional view as in FIG. 1 but showing analternate embodiment including means of adjusting calibration from theexterior of the meter.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings,and in particular to FIG. 1, numeral 10 indicates generally the axialflow turbine meter of this invention. It comprises a casing 12 ofcylindrical form, with flanges l3 and 14 by means of which it can beinserted into a liquid flow line in a conventional manner. There is acentral core which is cylindrical in form and somewhat streamlined. Thishas an upstream portion 16 and a downstream portion 18 which areseparated to provide space for the turbine wheel. The direction ofliquid flow is shown by the arrow 19.

The two parts 16, 18 of the central core are supported axially by meansof radial vanes 20 and 22, of which there can be any desired number suchas 4 which is shown in the drawings. Part 16 has a longitudinal centralaxial passageway 28 and, in like manner, part 18 has a passageway 74. Along bolt 30 received in pas-, sageways 28 and 74 support a bearingcylinder 36 and thrust bearing washers 34 and 35. A step in the diameter32 of bolt 30 retains the bearing cylinder 36 in proper relationship topart 16 of the central core. Wrench flats 72 on bolt 30 aid in assembly.Nuts 31 and 76 on each end of bolt 30 hold the vanes of the two centralcore sections 16 and 18 against the ends 24 and 26 of body 10.

Cooperating with the cylindrical bearing 36 is a tube 38 on which ismounted the hub 40 of the turbine rotor. The rotor comprises thiscylindrical hub 40, an annular plate 42, which is set perpendicular tothe axis, and a cylindrical flange 44. The annular plate is shown in thecenter of the wheel, although it can be positioned anywhere includingeither end of the hub.

In the form shown in the drawing it provides two annular cavities oneach side of the central annular plate 42 and bound on the inside andoutside by the hub and the cylindrical flange, respectively.

A cylindrical tubular extension 50 is shown applied to the inner end ofthe downstream portion of the central core 18.

While this is shown as being fastened to the core by means of screws 52,it could equally well be a unitary portion of the core itself. Being aseparate part, as shown, it can be an exchangable part, where parts ofdifferent dimensions providing difi'erent clearances between theextension 50 and the annular cavity. This is a way to change thecompensation for a different viscosity of liquid. Shown in dashed formas an extension of the leading portion of the core 16 is an extension 54similar to the extension 50, but fitted into the upstream side cavity inthe wall of the rotating wheel. By making these extensions 50 and 54separable as shown they can be of different sizes providing differentclearances. Either one or both can be used at the same time.

It is desirable to insure that the liquid in the annular cavity and inthe clearances between the wheel and the extensions has the sameviscosity liquid flowing as in the annular space between the core andthe casing. One way of accomplishing this is to drill a hole 58 (showndashed) axially through the leading portion 16 of the core, into theannular space in the wheel. Thus, the forward movement of the liquid inthe direction 19 will force some of it through the drilled hole 58 intothe annular space, through the clearances, and out into the annularpassage and through the wheel blades.

Similarly, two drilled holes 62 and 64 are shown in the downstreamportion 18 of the core with an angular portion 66, such that themovement of the liquid through the annular passage will force liquidthrough the tube 66 and passages 64 and 62 in accordance with the arrow68 into the annular depression on the downstream side of the wheel,through the apertures between the extension and the wheel, and inaccordance with arrow 70 out into the axial flowing liquid in theannular passage.

From this description it will be clear that while the embodiment shows aturbine wheel with a central annular plate and two annular depressionson either side, with core extensions into those depressions from theleading and trailing portions of the core, it would be equally possibleto provide extensions to the rotating wheel which would be fitted intoannular cavities in the ends of the leading and trailing portions of thecore. In the interest of making the rotating turbine wheel as simple andlight as possible it is more convenient to provide the annular cavitiesin the rotor and the extensions as parts of the core as shown.

Mounted on the tube 38 downstream from the rotor wheel, is a permanentmagnet 82 and a tooth wheel 84 which cooperate with a detecting element80 inserted from the outside of the casing through the wall of thecasing and through an opening 78 in the central core.

As the rotor turns, it will turn toothed wheel 84. The

flux passing to the detecting instrument 80, will vary, 4

thus, a pulsating flux is created which generates an electrical voltagein the detecting element in a manner well known in the art. Thispulsating electrical voltage can be amplified and can be used toindicate flow rate as on instrument 80A or to operate or controlelectrical instruments which can count the pulsations in a given timeand determine from that the rate of rotation of the turbine wheel. Froma prior calibration, the actual flow rate of liquid through the metercan be determined.

FIGS. 2 and 3 show in greater detail some of the features of the centralcore and of the extension ring 50, all of which has been described inconnection with FIG.

Reviewing again the operation of this invention, it is well known in theart that axial flow turbine meters of this type are sensitive toviscosity of the liquid flowing through the meter, such that when theviscosity is high, the meter will indicate a higher flow rate than whenthe same flow rate of a low viscosity liquid is being measured. In orderto correct for this over-indication with high viscosity liquids, thisinvention involves passing some of the liquid through a restrictedpassage between the rotating wheel and extensions to the cores, suchthat when the liquid is viscous, it will provide a drag on the rotorreducing the indication, and when the liquid is not viscous,correspondingly no correction will be applied because none is needed.The apparatus is simple, convenient, cheap, and rugged and does the samejob that many other instruments perform, which instruments are far morecomplicated and expensive than the device of this invention.

FIG. 4 shows an alternate embodiment of the invention in qwhich theclearance between the tubular extension and the rotor is variable bymeans externally of the meter body. Tubular extension 54 is slidablypositioned in a tubular recess 86 in core portion 16. Extension 54 hasspaced openings 88 (only one of which is shown) each of which slidablyreceives a bolt 90 threaded into core portion 16. Each opening 88includes a larger diameter portion 88A which slidably receives the head90A of the bolt. A spring 92 is positioned in each opening 88A beneathbolt head 90A resiliantly urging the extension 54 away from rotorannular plate 42.

Rotatably received in an opening 94 in body 12 and an opening 96 in coreportion 16 is a shaft 98. Afflxed to the inner end of shaft 94 is a cam100 which engages extension 54. Exterior of body 12 is a handle 102 bywhich shaft 94 is rotatably positioned, which, by the action of cam 100,adjusts the clearance between extension 54 and the rotor annular plate42. This enables the drag imposed on the rotor to be adjusted fordifferent fluid viscosities.

While the invention has been described with a certain degree ofparticularity, it is manifest that many changes may be made in thedetails of construction and the arrangement of components. It isunderstood that the invention is not to be limited to the specificembodiment set forth herein by way of exemplifying the invention, butthe invention is to be limited only by the scope of the attached claimor claims, including the full range of equivalency to which each elementor step thereof is entitled.

What is claimed:

1. In an axial flow turbine meter for metering the flow of liquids,which generally comprise:

a cylindrical casing;

-a cylindrical streamlined core coaxial with said casan annular passagebetween said core and said casa metering wheel carrying a plurality ofcircumferentially spaced blades exposed in said annular passage androtatable about the axis of said casing in response to the flow of saidliquid, said core in two parts, one upstream and the other downstream ofsaid metering wheel, and means to indicate the rotation of said wheel,the improvement comprising; a. said metering wheel comprising a hubrotatable about a fixed shaft supported by one of said core parts;

b. cylindrical flange coaxial with said hub supported from said hubmeans of an annular disk, said flange supporting said plurality ofcircumferentially spaced radial blades, said hub, said disk, and saidflange forming an annular depression on at least one side of said disk,and

c. extension cylindrical tubular means on the end of at least one ofsaid core parts inserted into said annular depression;

whereby when the liquid being metered has a high viscosity, and themeter tends to indicate a flow rate which is too high, said viscousliquid in the space between said depression and said extension willprovide a viscous drag on said wheel to reduce the error in theindicated flow rate.

2. The meter as in claim 1 in which said extension is part of thedownstream part of said core.

3. The meter as in claim 2 in which said extension comprises acylindrical ring attached to the upstream end of the downstream part ofsaid core.

4. The meter as in claim 3 including tubular means to convey liquid fromsaid annular passage into the- I space inside said ring, whereby saidliquid will flow through the space between said 5. The meter as in claim1 in which said extension is part of the upstream part of said core.

6. The meter as in claim 1 in which the clearance between said extensioncylindrical tubular means and said metering wheel annular disk isadjustable.

7. The meter as in claim 1 in which said clearance is adjustable bymeans extending externally of the meter.

8. The meter as in claim 5 including at least one hole drilledlongitudinally in the upstream part of said core leading into the spaceradially within said extension, whereby part of the liquid approachingsaid wheel is carried through said hole into said annular depression onthe upstream side of said wheel and between said extension and saidwheel.

1. In an axial flow turbine meter for metering the flow of liquids,which generally comprise: a cylindrical casing; a cylindricalstreamlined core coaxial with said casing; an annular passage betweensaid core and said casing; a metering wheel carrying a plurality ofcircumferentially spaced blades exposed in said annular passage androtatable about the axis of said casing in response to the flow of saidliquid, said core in two parts, one upstream and the other downstream ofsaid metering wheel, and means to indicate the rotation of said wheel,the improvement comprising; a. said metering wheel comprising a hubrotatable about a fixed shaft supported by one of said core parts; b.cylindrical flange coaxial with said hub supported from said hub meansof an annular disk, said flange supporting said plurality ofcircumferentially spaced radial blades, said hub, said disk, and saidflange forming an annular depression on at least one side of said disk,and c. extension cylindrical tubular means on the end of at least one ofsaid core parts inserted into said annular depression; whereby when theliquid being metered has a high viscosity, and the meter tends toindicate a flow rate which is too high, said viscous liquid in the spacebetween said depression and said extension will provide a viscous dragon said wheel to reduce the error in the indicated flow rate.
 2. Themeter as in claim 1 in which said extension is part of the downstreampart of said core.
 3. The meter as in claim 2 in which said extensioncomprises a cylindrical ring attached to the upstream end of thedownstream part of said core.
 4. The meter as in claim 3 includingtubular means to convey liquid from said annular passage into the spaceinside said ring, whereby said liquid will flow through the spacebetween said ring and said wheel into said passage.
 5. The meter as inclaim 1 in which said extension is part of the upsTream part of saidcore.
 6. The meter as in claim 1 in which the clearance between saidextension cylindrical tubular means and said metering wheel annular diskis adjustable.
 7. The meter as in claim 1 in which said clearance isadjustable by means extending externally of the meter.
 8. The meter asin claim 5 including at least one hole drilled longitudinally in theupstream part of said core leading into the space radially within saidextension, whereby part of the liquid approaching said wheel is carriedthrough said hole into said annular depression on the upstream side ofsaid wheel and between said extension and said wheel.